Former Tiananmen Square protester Yang Jianli, who spent five years in prison in China, talked to a packed room Monday night in an event organized by the Chinese Students Association.

“When I talk about my story, I say it’s bigger than myself,” Yang proclaimed while introducing himself to a packed room of students at an event organized by the Chinese Student Association.

Yang decided to leave China shortly after the protests in 1989. When Yang returned years later, he was caught traveling with fake identification papers and imprisoned for five years.

Yang was born in 1963, three years before the Cultural Revolution, to a Communist Party official and his wife. The Cultural Revolution was started by Mao Zedong to mobilize the general public behind him and against other top party officials that were seeking to usurp power.

Growing up, Yang saw his father beaten, subjected to public humiliation,sent to the countryside, and then brought back without any explanation. When Yang was 7, he came across construction workers singing as they were working. He recounted how the workers asked who his parents were and when he responded, they immediately turned back to their work and began singing. The song that they were singing was one insulting his father and the policies he helped to implement. From that moment, when Yang realized his father was involved in the oppression of the people, he became interested in politics and the rights of Chinese citizens.

After Mao died in 1976, Deng Xiaoping took power and reopened universities. Yang entered the Beijing Normal University at the age of 15 in pursuit of a mathematics degree.

While attending university, Yang was recruited by the Party looking for new, younger members. Thinking that he could challenge the system from the inside, Yang accepted membership to the party but soon found that the party was toxic, and that he couldn’t change anything in this way.

“We did not change the party, the party changed us,” he said.

In response to the toxicity of the party membership, Yang transferred to the University of California, Berkeley to finish his master’s and Ph.D. While working on his mathematics doctorate, the student protests in Tiananmen Square in response to an increasingly controlling government began. Yang tried to do what he could to help the movement in America by leading support movements in San Francisco. But what he saw happening in China soon drew him back.

“I remember it was May 13, I watched the TV while eating, I saw for the first time armored police beating students and blood running down their faces,” Yang said. “And I couldn’t take it-I decided in that moment to return to Beijing to participate on the ground.”

While protesting in Beijing, Yang saw over one million people gather in Tiananmen Square at the beginning of a hunger strike, the instillation of martial law, and the violent transition to attacking the protestors.

Early on June 4, 1989, while traveling back to Tiananmen Square with a friend, Yang saw troops march on the protestors and open fire on the students. Yang recounted seeing tanks drive down the streets, running people over and firing on the crowds

“The troops opened fire to both sides and each time when we heard a gunshot we would drop down to the ground,” he said. “It was so surreal, we didn’t think that it was real until we saw the blood.”

After witnessing the violent attacks on the protestors, Yang felt that he could be of the most help working outside of China, and he returned to the U.S. In 2002, he decided to return to China, intending to stay for two weeks. He did not want to travel under his own name and used his friend’s passport, but as he was trying to leave, he was arrested in Kunming airport.

Yang recounted how after being held at the airport, he was transferred to Beijing’s Second Prison for Democratic Work, where he was initially held in solitary confinement for 15 months. He described solitary confinement as extremely mentally taxing, and one of the hardest times of his life. After the 15 months, Yang met with his lawyer and learned that his family and the U.S government were petitioning for his freedom.

Yang served five years in prison, and with the help of activists petitioning on his behalf after his release, was able to obtain a passport and travel back to the United States. Since then Yang has been working to expand democracy in China.

Yang said that, over the past three to four years, the current Chinese president, Xi Jinping, has been implementing more oppressive policies. He worries that Xi will not name a successor this coming fall, breaking with the government norm.

“China has great, great potential, but we have to change the nature of the political system and it will not come without effort,” he said.